C3 Chevrolet Corvette Sting Ray ZL1 Engine

The rare ZL1 C3 Chevrolet Corvette Sting Ray came with the ZL1 engine. This engine was a 427-cubic inch (7 L) all-aluminum big block V-8 that supposedly put out approximately 550 hp. Only a few C3 Chevy Corvettes were actually shipped with this engine. However, many racers were later upgraded to the ZL1. The reason so few Vettes were ordered with this engine option was cost: it added more than a third more to the price of a new Corvette at the time, making it the priciest engine GM had offered to date. Another factor was that the engine had not been as carefully tested as its contemporary, the L-88. After extensive experimentation to rid it of porosity problems which caused leaks, the engine was finally made available in 1968 and was installed in a number of Corvettes and Camaros, mostly as crate engines.

The ZL1 engine was an original design, produced “from the ground up.”
The engineers who created it learned much from its predecessor the
283-cubic inch all-aluminum engine. The two important differences
between the ZL1 and the L-88 were increased support webbing and greater
block thickness.